flowchart LR
  Start[Start]
  Stop[Stop]
  Start --> Plus([<tt>+</tt>]) --> Stop
  Start --> Minus([<tt>-</tt>]) --> Stop
  Start --> Not([<tt>not</tt>]) --> Stop
  Start --> At([<tt>@</tt>]) --> Stop
  Start --> AtAt([<tt>@@</tt>]) --> Stop